Fermi level pinning at the Dirac point in epitaxial multilayer graphene

A paper on evidence of Fermi level pinning at the Dirac point in epitaxial multilayer graphene has has been published in Physical Review B by the group at CNRS-LPA. The authors investigated the temperature-dependent conductivity of epitaxial multilayer graphene using THz time domain spectroscopy and show evidence that the Fermi level in quasi-neutral graphene layers is pinned at the Dirac point by mid-gap states. The authors demonstrated that the scattering mechanisms result from the interplay between mid-gap states, which dominate in the vicinity of the Dirac point, and short-range potentials that govern at higher energies (>8 meV). These results highlight the potential of multilayer epitaxial graphene for probing low-energy Dirac particles and also for THz optics.